1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // SampleMap implements HistogramSamples interface. It is used by the 6 // SparseHistogram class to store samples. 7 8 #ifndef BASE_METRICS_SAMPLE_MAP_H_ 9 #define BASE_METRICS_SAMPLE_MAP_H_ 10 11 #include <stdint.h> 12 13 #include <map> 14 #include <memory> 15 16 #include "base/compiler_specific.h" 17 #include "base/macros.h" 18 #include "base/metrics/histogram_base.h" 19 #include "base/metrics/histogram_samples.h" 20 21 namespace base { 22 23 // The logic here is similar to that of PersistentSampleMap but with different 24 // data structures. Changes here likely need to be duplicated there. 25 class BASE_EXPORT SampleMap : public HistogramSamples { 26 public: 27 SampleMap(); 28 explicit SampleMap(uint64_t id); 29 ~SampleMap() override; 30 31 // HistogramSamples: 32 void Accumulate(HistogramBase::Sample value, 33 HistogramBase::Count count) override; 34 HistogramBase::Count GetCount(HistogramBase::Sample value) const override; 35 HistogramBase::Count TotalCount() const override; 36 std::unique_ptr<SampleCountIterator> Iterator() const override; 37 38 protected: 39 // Performs arithemetic. |op| is ADD or SUBTRACT. 40 bool AddSubtractImpl(SampleCountIterator* iter, Operator op) override; 41 42 private: 43 std::map<HistogramBase::Sample, HistogramBase::Count> sample_counts_; 44 45 DISALLOW_COPY_AND_ASSIGN(SampleMap); 46 }; 47 48 } // namespace base 49 50 #endif // BASE_METRICS_SAMPLE_MAP_H_ 51